Phase and interface engineering of nickel carbide nanobranches for efficient hydrogen oxidation catalysis

Author(s):  
Wangjin Ji ◽  
Changhong Zhan ◽  
Deyu Li ◽  
Yong Xu ◽  
Ying Zhang ◽  
...  

A heterogeneous Ni/Ni3C interface has been constructed through carefully annealing a classic metal carbide of Ni3C, where the strong interfacial synergy can regulate the binding strengths of *H and *OH and thus enhance the HOR performance.

2010 ◽  
Vol 46 (45) ◽  
pp. 8618 ◽  
Author(s):  
Jenny Y. Yang ◽  
Shentan Chen ◽  
William G. Dougherty ◽  
W. Scott Kassel ◽  
R. Morris Bullock ◽  
...  

2021 ◽  
Vol 27 (3) ◽  
Author(s):  
Anna Rovaletti ◽  
Claudio Greco ◽  
Ulf Ryde

AbstractThe MoCu CO dehydrogenase enzyme not only transforms CO into CO2 but it can also oxidise H2. Even if its hydrogenase activity has been known for decades, a debate is ongoing on the most plausible mode for the binding of H2 to the enzyme active site and the hydrogen oxidation mechanism. In the present work, we provide a new perspective on the MoCu-CODH hydrogenase activity by improving the in silico description of the enzyme. Energy refinement—by means of the BigQM approach—was performed on the intermediates involved in the dihydrogen oxidation catalysis reported in our previously published work (Rovaletti, et al. “Theoretical Insights into the Aerobic Hydrogenase Activity of Molybdenum–Copper CO Dehydrogenase.” Inorganics 7 (2019) 135). A suboptimal description of the H2–HN(backbone) interaction was observed when the van der Waals parameters described in previous literature for H2 were employed. Therefore, a new set of van der Waals parameters is developed here in order to better describe the hydrogen–backbone interaction. They give rise to improved binding modes of H2 in the active site of MoCu CO dehydrogenase. Implications of the resulting outcomes for a better understanding of hydrogen oxidation catalysis mechanisms are proposed and discussed.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changhong Zhan ◽  
Yong Xu ◽  
Lingzheng Bu ◽  
Huaze Zhu ◽  
Yonggang Feng ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Duan ◽  
Zi-You Yu ◽  
Li Yang ◽  
Li-Rong Zheng ◽  
Chu-Tian Zhang ◽  
...  

Abstract Hydroxide exchange membrane fuel cells offer possibility of adopting platinum-group-metal-free catalysts to negotiate sluggish oxygen reduction reaction. Unfortunately, the ultrafast hydrogen oxidation reaction (HOR) on platinum decreases at least two orders of magnitude by switching the electrolytes from acid to base, causing high platinum-group-metal loadings. Here we show that a nickel-molybdenum nanoalloy with tetragonal MoNi4 phase can catalyze the HOR efficiently in alkaline electrolytes. The catalyst exhibits a high apparent exchange current density of 3.41 milliamperes per square centimeter and operates very stable, which is 1.4 times higher than that of state-of-the-art Pt/C catalyst. With this catalyst, we further demonstrate the capability to tolerate carbon monoxide poisoning. Marked HOR activity was also observed on similarly designed WNi4 catalyst. We attribute this remarkable HOR reactivity to an alloy effect that enables optimum adsorption of hydrogen on nickel and hydroxyl on molybdenum (tungsten), which synergistically promotes the Volmer reaction.


2018 ◽  
Vol 10 (35) ◽  
pp. 29425-29434 ◽  
Author(s):  
Yingwei Li ◽  
Yuxiang Chen ◽  
Stephen D. House ◽  
Shuo Zhao ◽  
Zahid Wahab ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changhong Zhan ◽  
Yong Xu ◽  
Lingzheng Bu ◽  
Huaze Zhu ◽  
Yonggang Feng ◽  
...  

AbstractHigh-entropy alloys (HEAs) with unique physicochemical properties have attracted tremendous attention in many fields, yet the precise control on dimension and morphology at atomic level remains formidable challenges. Herein, we synthesize unique PtRuNiCoFeMo HEA subnanometer nanowires (SNWs) for alkaline hydrogen oxidation reaction (HOR). The mass and specific activities of HEA SNWs/C reach 6.75 A mgPt+Ru−1 and 8.96 mA cm−2, respectively, which are 2.8/2.6, 4.1/2.4, and 19.8/18.7 times higher than those of HEA NPs/C, commercial PtRu/C and Pt/C, respectively. It can even display enhanced resistance to CO poisoning during HOR in the presence of 1000 ppm CO. Density functional theory calculations reveal that the strong interactions between different metal sites in HEA SNWs can greatly regulate the binding strength of proton and hydroxyl, and therefore enhances the HOR activity. This work not only provides a viable synthetic route for the fabrication of Pt-based HEA subnano/nano materials, but also promotes the fundamental researches on catalysis and beyond.


The Analyst ◽  
2020 ◽  
Vol 145 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Wanda V. Fernandez ◽  
Rocío T. Tosello ◽  
José L. Fernández

Gas diffusion electrodes based on nanoporous alumina membranes electrocatalyze hydrogen oxidation at high diffusion-limiting current densities with fast response times.


2009 ◽  
Vol 129 (4) ◽  
pp. 548-552
Author(s):  
Atsushi Yamamoto ◽  
Takashi Kusano ◽  
Tsutomu Okutomi ◽  
Kunio Yokokura ◽  
Mitsutaka Homma

2018 ◽  
Author(s):  
Asim Maity ◽  
Sung-Min Hyun ◽  
Alan Wortman ◽  
David Powers

<p>Hypervalent iodine(V) reagents, such as Dess-Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to access these reagents from O2 would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. Here, we couple aerobic oxidation of iodobenzenes with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. Further, the developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.</p>


2019 ◽  
Author(s):  
Wugen Huang ◽  
qingfei liu ◽  
Zhiwen Zhou ◽  
Yangsheng Li ◽  
Yong Wang ◽  
...  

Despite tremendous importance in catalysis, the design and improvement of the oxide- metal interface has been hampered by the limited understanding on the nature of interfacial sites, as well as the oxide-metal interaction (OMI). Through the construction of well-defined Cu<sub>2</sub>O-Pt, Cu<sub>2</sub>O-Ag, Cu<sub>2</sub>O-Au interfaces, we found that Cu<sub>2</sub>O Nanostructures (NSs) on Pt exhibit much lower thermal stability than on Ag and Au, although they show the same surface and edge structures, as identified by element-specific scanning tunneling microscopy (ES-STM) images. The activities of the Cu<sub>2</sub>O-Pt and Cu<sub>2</sub>O-Au interfaces for CO oxidation were further compared at the atomic scale and showed in general that the interface with Cu<sub>2</sub>O NSs could annihilate the CO-poisoning problem suffered by Pt group metals and enhance the interaction with O<sub>2</sub>, which is a limiting step for CO oxidation catalysis on group IB metals. While both interfaces could react with CO at room temperature, the OMI was found to determine the reactivity of supported Cu<sub>2</sub>O NSs by 1) tuning the activity of interfacial oxygen atoms and 2) stabilizing oxygen vacancies or vice versa, the dissociated oxygen atoms at the interface. Our study provides new insight for OMI and for the development of Cu-based catalysts for low temperature oxidation reactions.


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